in the 2+ years of ownership, I've had to add coolant twice. The first time it took nearly half a jug to fill it back up. Took it to the dealer for a checkup and they said it had no leaks anywhere.
Second time it probably took about 2 cups to fill it back up... still no leaks.
As others have stated, water is fine... but next time you are at the dealer, it might not hurt to pick up a jug of coolant... Because there will be a next time.
